1. Field of the Invention
The present invention relates to the field of computer systems that are battery operated and have display screens. More specifically, the present invention relates to portable electronic devices and systems.
2. Related Art
As the components required to build a computer system have reduced in size, new categories of computer systems have emerged. One of the new categories of computer systems is the xe2x80x9cpalmtopxe2x80x9d computer system. A palmtop computer system is a computer that is small enough to be held in the hand of a user and can therefore be xe2x80x9cpalm-sized.xe2x80x9d Most palmtop computer systems are used to implement various Personal Information Management (PIM) applications such as an address book, a daily organizer and electronic notepads, to name a few. Palmtop computers with PIM software have been know as Personal Digital Assistants (PDAs). Many PDAs have a small and flat display screen associated therewith.
In addition to PDAs, display screens have also been implemented within other portable electronic devices, such as cell phones, electronic pagers, remote control devices and other wireless portable devices.
These portable electronic devices, such as PDAs, are often battery powered. Some portable electronic devices utilize rechargeable batteries and others use cells that need to be replaced after some limited period of use. As portable electronic devices become more complex electronically, their power consumption rates have also increased. Because they have limited battery energy, some PDAs and other electronic devices, such as cells phone, electronic pagers, etc., have relatively short operational periods between which battery replacements or recharging is required. With respect to rechargeable PDAs, cell phones, electronic pagers, etc., they typically have little more than a day of stored battery energy before they need to be recharged. Therefore, it would be desirable to provide an electronic device having a screen that functioned in a way to enhance the device""s battery life.
Certain PDAs manage their battery life in an intelligent manner. For instance, if the battery life of certain PDAs falls below a predetermined low level, the user is given a screen message indicating that a battery recharge or replacement is needed and should be done right away. In this manner, the user can perform corrective action before any information is lost. Therefore, it would be desirable to provide an electronic device having a screen that enhanced and managed the device""s battery life in an intelligent manner.
Some color flat panel displays utilize a back lighting element, such as a cold cathode fluorescent (CCF) tube. These elements consume a relatively large amount of energy from a battery operated device. It would be desirable to provide an electronic device that offered a color display but also managed the device""s battery life in an intelligent manner.
Accordingly, embodiments of the present invention provide an electronic device, e.g., a cell phone, PDA, electronic pager, etc., having a screen also that functions in a way to enhance the device""s battery life. Embodiments also provide an electronic device having a screen that also enhances and manages the device""s battery life in an intelligent manner. Embodiments also provide an electronic device that offers a multi-mode color display that also manages the device""s battery life in an intelligent manner. The present invention provides these advantages and others not specifically mentioned above but described in the sections to follow.
A method and system are described herein for enhancing the life of a battery within a portable or otherwise battery operated electronic device. The method and system provide user selectable display modes, e.g., from color to monochrome, that can be changed in order to enhance the life of the battery. In one embodiment, monochrome display mode consumes less power than color display mode. For instance, the monochrome display mode can be selected by the user when the battery level is detected as falling below a predefined threshold. In one embodiment, the electronic device is a hand held computer system with a multi-mode display device. When the battery level is automatically detected as falling below a preselected level, a message is generated on the computer display screen. The message informs the user that the display mode of the screen can be changed to enhance the battery life. If selected, the display mode can change from color to monochrome thereby saving power because the monochrome display does not utilize a back-lighting element. In one embodiment, color sequential techniques are used to provide a flat panel color/monochrome display. Within the display, a transreflective layer provides reflective light for monochrome applications and bright light color applications. When the battery energy returns to normal levels, the color display mode can be re-entered automatically. It is appreciated that the display mode changes can also be performed automatically if the battery level falls below certain critical levels.
More specifically, an embodiment of the present invention includes a portable electronic device comprising: a battery; a processor coupled to bus; an input device coupled to the bus; a multi-mode display device coupled to the bus; a memory unit coupled to the bus wherein the memory unit contains processor instructions that when executed implement a method of enhancing battery life comprising the steps of: a) detecting a battery energy level of the portable electronic device below a first predetermined level, wherein the portable electronic device has a multi-mode display device; b) in response to step a), placing the multi-mode display device into a monochrome display mode to enhance remaining battery life of the portable electronic device; c) detecting the battery energy level of the portable electronic device above a second predetermined level; and d) in response to step c), placing the multi-mode display device into a color display mode.
Embodiments include the above and wherein the multi-mode display device comprises: a) selectively energized multi-color lighting elements; b) a color flat panel display layer utilizing color sequential scanning processes; and c) a transreflective layer positioned between the multi-color lighting elements and the color flat panel display layer. Embodiments include the above and wherein the step b) of the method comprises the steps of: b1) displaying a message on the multi-mode display device indicating a low battery state and also indicating a user selection between color and monochrome display modes; and b2) in response to a user selection of the monochrome display mode, placing the multi-mode display device into the monochrome display mode and wherein the step b) further comprises the step of b3) automatically placing the multi-mode display device into the monochrome display mode, regardless of the user selection, provided the battery level is below a predetermined critical low level.